Ink jet printing is a well-known technique by which printing is accomplished without contact between the printing device and the substrate on which the printed characters are deposited. Briefly described, ink jet printing involves the technique of projecting a stream of ink droplets to a surface and controlling the direction of the stream electronically so that the droplets are caused to form the desired printed message on that surface.
The technique of jet ink printing or non-contact printing is particularly well suited for application of characters onto irregularly shaped surfaces, including, for example, the bottom of glass, metal, or plastic containers, generally used for holding beverage, cosmetic, pharmaceutical, liquor, and health care products.
Reviews of various aspects of ink jet printing can be found in these publications: Kuhn et al., Scientific American, April, 1979, 162-178; and Keeling, Phys. Technol., 12(5), 196-303 (1981). Various ink jet apparatuses are described in the following U.S. Pat. Nos.: 3,060,429, 3,298,030, 3,373,437, 3,416,153, and 3,673,601.
In general, an ink jet composition must meet certain rigid requirements to be useful in ink jet printing operations. These relate to viscosity, resistivity, solubility, compatibility of components and wettability of the substrate. Further, the ink must be quick-drying and smear resistant, resist rubbing, and be capable of passing through the ink jet nozzle without clogging, and permit rapid cleanup of the machine components with minimum effort.
In addition, the ink must meet certain other requirements. The messages printed on the substrates must resist moisture. The bottles, such as beverage bottles, may be exposed to humid conditions during warehousing and shipping to different parts of the country and in different seasons. The messages should not be damaged by the hot and cold humid conditions. If condensation occurred on the surface, the printed messages should not be damaged by the condensation. In addition, if the containers such as beer bottles or cans are immersed in ice water for chilling, the messages should not disintegrate or be damaged by the ice water.
There has been significant developmental activity in the area of ink compositions suitable for ink jet printing, and several jet ink compositions are known. Some examples of known inks are set forth below.
UK patent application Serial No. GB 2,105,735 discloses a jet ink composition comprising an oil soluble dye-impregnated polyurethane latex dispersed in an aqueous medium.
U.S. Pat. No. 4,155,768 discloses an ink for use in ink jet printers which contains a water soluble dye and a polyamine containing 6 or fewer nitrogen atoms per molecule, with the ink having a pH of 8 or below.
U.S. Pat. No. 4,197,135 discloses an ink for use in ink jet printers which contains a water soluble dye and a polyamine containing 7 or more nitrogen atoms per molecule, with the ink composition having a pH of 8 or above.
U.S. Pat. No. 4,680,332 discloses a jet ink composition comprising a water insoluble polymer such as a polyacrylate dispersed in a liquid medium, the polymer containing therein an oil soluble dye, and a nonionic stabilizer permanently attached thereto.
U.S. Pat. No. 4,692,188 discloses a process for the preparation of jet ink compositions, comprising (1) dissolving in a water-immiscible organic solvent a polymer composition and an organic oil soluble dye; (2) adding an aqueous phase water surfactant mixture thereto; (3) affecting emulsification thereof; and (4) subsequently evaporating from the aforementioned mixture the solvent thereby resulting in an ink with the dye trapped in the polymer particles suspended in the aqueous phase. The polymer compositions include polycarbonates, polystyrene, polymethacrylates and copolymers thereof.
U.S. Pat. No. 5,080,716 discloses a jet ink composition comprising a recording agent, a liquid medium capable of dissolving or dispersing the recording agent, and a substituted benzene or toluene sulfonamide compound.
U.S. Pat. No. 5,098,475 discloses an ink composition comprising a solution with a dendrimer colored with a dye or dyes covalently attached thereto.
U.S. Pat. No. 5,100,470 discloses an ink jet ink comprising a water soluble dye, water with or without a water soluble organic solvent, and sufficient polyalkylene polyamine to provide the ink with a pH of at least 9.
U.S. Pat. No. 5,120,361 discloses an aqueous ink composition comprised of a dendrimer, and a dye.
U.S. Pat. No. 5,131,949 discloses a jet ink composition including a recording agent, a liquid medium capable of dissolving or dispersing the recording agent, and a compound having an amide group.
U.S. Pat. No. 5,207,825 discloses a jet ink composition which comprises an aqueous liquid vehicle, a colorant, and a polymeric additive which is a substituted bisphenol A derivative.
U.S. Pat. No. 5,213,613 discloses a jet ink comprising a recording agent and a liquid medium capable of dissolving or dispersing the recording agent therein, wherein the ink contains an imide compound and at least one compound selected from the group consisting of urea, thiourea and derivatives thereof, and volatile alkaline compounds.
U.S. Pat. Nos. 5,215,577 and 5,178,671 disclose jet ink compositions comprising a recording agent and a liquid medium for dissolution or dispersion thereof, the recording agent being an aromatic sulfonated diazo compound.
U.S. Pat. No. 5,254,158 discloses an ink composition which comprises an aqueous liquid vehicle, a colorant, and an additive selected from the group consisting of amine alkoxylates, sorbitan monoester alkoxylates, alkylene oxide adducts of glycerin, and mixtures thereof.
U.S. Pat. No. 5,254,159 discloses an ink composition comprising water, an anionic dye, and a polyamine such as N,N'-bis(3-aminopropyl)-1,2-ethylenediamine or a dendrimer.
U.S. Pat. No. 5,256,193 discloses an aqueous ink composition comprised of a dendrimer, and a dye comprised of a porphyrin chromophore.
U.S. Pat. No. 5,266,106 discloses an aqueous ink composition comprised of a dye and a grafted dendrimer such as a dendrimer grafted with a nonionic alkylene oxide oligomer.
Many of the aforementioned patents disclosing ink compositions do not address the condensation and water resistance of printed messages on glass, metal, plastic, and rubber surfaces, and the ink compositions are considered generally not suitable for providing water resistant messages on glass, metal, plastic, and rubber surfaces.
Thus, there exists a need for jet ink compositions meeting certain rigid requirements. There exists a need for jet ink compositions that provide high quality messages on surfaces such as glass, metal, plastic, and rubber container surfaces. There exists a need for jet ink compositions whose printed messages resist moisture. There exists a need for jet ink compositions whose dried messages do not smear or degrade when exposed to hot and cold humid conditions. There exists a need for jet ink compositions whose printed messages do not smear or degrade when the dried messages are exposed to ice water.
It is therefore an object of the present invention to provide jet ink compositions that provide high quality messages on surfaces such as glass, metal, plastic, and rubber container surfaces. It is also an object of the present invention to provide jet ink compositions whose printed messages resist moisture. It is a further object of the present invention to provide jet ink compositions whose printed messages do not smear or degrade when exposed to hot and/or cold humid conditions. It is also an object of the present invention to provide jet ink compositions whose printed messages do not smear or degrade when exposed to ice water.